Model Output Discussion - 1st - 7th January

[Duane S.]

Not really any further on this morning as the models dish out more poor charts. The ECM at 10 days is again playing at a link up beween the the highs and I really do feel that this is where the money is. The troughing over Greece is one to watch. The GFS has potential but never delivers in terms of signs of heading into sustained cold.

Frustrating I know but I still think we are going to have a different 'feel' to the charts in a week's time as they start to get a better grip of the warmings etc and the effect on the topospheric vortex.

[mountain shadow]

Very poor runs this morning. If anything looking more Zonal. A few interesting ensembles at post 300 hours (as usual), but most just show the status quo.

Indeed Jason. Whilst any reminant of the PV remains locked into Greenland any upstream pattern change or stratospheric warming would appear to have little impact on our small islands,

Perhaps we will get a change in late January/early February?

[karyo]

Another day another round of disappointing model output!

You need to view the ECM north hemispheric chart to see some potential past 216 hours but that's been showing for several days now and doesn't want to come any closer.

Karyo

[Frosty.]

The Gfs 00z op run shows the jet becoming much more powerful again after a brief quieter phase next week, the charts in deep FI are almost identical to what we have seen in the last month (just like we had with the cold strat) with mainly mild/average zoneality as high pressure again locks in to the south and lows blast across the north but into next week there is a break in the bad weather being forecast for southern britain (mainly further south) at least with high pressure in control, the ecm 00z is a bit more bullish about the anticyclonic domination next week for the south so at least there would be some fog and frost, especially for the southeast, low pressure to the north of the uk looks like keeping most of northern britain in a more changeable/unsettled regime throughout apart from later this weekend and the start of next week before the ridge subsides.

Edited January 3, 2012 by Frosty039

[nick sussex]

Another day another round of disappointing model output!

You need to view the ECM north hemispheric chart to see some potential past 216 hours but that's been showing for several days now and doesn't want to come any closer.

Karyo

I think everyones tired of hearing the word potential and as i said yesterday when rubbishing the GEFS ensembles, regardless of what these show in FI its upto an operational run to remove the PV and stick with this for several days, so its the same old story from the ECM today, the chart with potential remains marooned at 240hrs.

Will this actually get closer?

Regarding the strat warming and whether this will effect the output, its upto the second warming due in about a week, this may weaken the PV sufficiently to allow that east Pacific ridge to finally dislodge it from its current holiday home in Greenland.

[wolvesfan]

Morning all,

Model output not good for cold again,previous flirts with trying to rise heights further north now gone for the time being,ensembles now supporting further mild also.

http://www.wetterzen...berdeen_ens.png

Background signals are better but the Greenland vortex still firmly in charge,it needs another hammer blow.

[Jason M]

Interesting developments on the 06Z run. Outcome looks no different, but this afternoons input will be more eagerly watched if charts like this start appearing again!

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=150&mode=0

[SP1986]

Interesting developments on the 06Z run. Outcome looks no different, but this afternoons input will be more eagerly watched if charts like this start appearing again!

http://www.meteociel...&ech=150&mode=0

I see what you mean, but without that PV dying down over Greenland, it will just aid the conveyer of zonality into northeast Europe and beyond. (Given what that particular outputs shows). The Balkans and Greece would probably do well from that situation in terms of cold.

[Tom Montalbano]

Yes Jason SP,

GFS 06z trying to build heights over Scandinavia as early as t147, as the PV edges west away from Greenland.

http://hw.nwstatic.co.uk/gfsimages/gfs.20120103/06/147/h500slp.png

But heights lower again as PV back over Greenland again.

http://hw.nwstatic.co.uk/gfsimages/gfs.20120103/06/189/h500slp.png

Will be interesting to see where that sits in the ensembles.

Regards,

Tom.

[BLAST FROM THE PAST]

Again the date around 7-10th looks interesting and a return to raging zoneality after this I would treat with caution unless of course you are 'wanting' it, it isn't nailed far from it, who saw how nailed posts failed in Dec. A positive spin, no Bartlett set up and some amplifying and ridge appearing which hasn't been modelled well, only showing recently...again... so take the 'default' FI outlook with a pinch of salt. Remember the southerly tracking LP 15-17 Dec which 'appeared' on the models only a couple of days before? Yes they showed it 7days before but quickly ditched the idea, ALL of them only to bring the feature back almost on the 11th hour....so lots can change at short notice so nothing is in charge down the line, it hasn't happened yet [silverline knows what I mean]. Keep one's eye on this period and see how it further develops, its still 4-7 days away this period. 06z around 132 onwards is most encouraging/interesting.

And I am surprised how anyone can think that December was a rubbish month, weatherwise it chucked it all at the UK...superb.

BFTP

Edited January 3, 2012 by BLAST FROM THE PAST

[Cecil Hogmanay Melchett]

I admire anyone being optimistic in the face of some woeful model output again this morning!

All 3 main models show a persistant cell of HP to our south and the limpet PV to the North West.

At some point this pattern will have to break but it looks like ruining at least half (and probably more)the Winter this time round.

Edited January 3, 2012 by happy days

[Osbourne One-Nil]

Blast, you have to admit though, in the model discussion thread, it's fair to discuss the models and what they're showing. Whilst your viewpoint is perfectly justified, I do think it would be a bit more helpful if you could explain in a bit more depth than "because it didn't happen last time".

Happy Days - I imagine you admire anyone who's optimistic, full stop.

[Tom Montalbano]

Despite the Operational being uninspiring, some interest amongst the other ensemble members post t192.

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=192&code=0&mode=0&carte=0

Regards,

Tom

[Cecil Hogmanay Melchett]

Blast, you have to admit though, in the model discussion thread, it's fair to discuss the models and what they're showing. Whilst your viewpoint is perfectly justified, I do think it would be a bit more helpful if you could explain in a bit more depth than "because it didn't happen last time".

Happy Days - I imagine you admire anyone who's optimistic, full stop.

Ozzy its hard to be optimisitc when we see the same repetative output day after day week after week.

BTFP,Dec came in well above average with little or no snow for the majority(maybe vast majority)and a wasp was seen on stage at the darts,in late Dec.From a coldies POV,thats not great,is it.

:lol:

06z GFS continues the well established theme of +NAO dominance.

[SP1986]

Despite the Operational being uninspiring, some interest amongst the other ensemble members post t192.

http://www.meteociel...&mode=0&carte=0

Regards,

Tom

From what I can see, PB 3, and 15 shows potentially some scope for inversions with a continental source of air, PB 9 is flirting with the idea of cold zonality (potential snowfall later on), the rest look as the operational does, either a zonal flow, or high pressure settling over the top of the Isles, with relatively mild air trapped in its core.

Regarding optimism and negativity, well in my view these shouldn't even come into the model output discussion, although some will disagree. I haven't seen any negativity, although hints of it from those who are perhaps expecting a pattern change today or tomorrow. If it happens it happens, if it doesn't it doesn't, personally I'm not going to lose sleep if the models don't deliver a colder scenario, but I suppose these situations do keep us going... will it won't it?

[BLAST FROM THE PAST]

Blast, you have to admit though, in the model discussion thread, it's fair to discuss the models and what they're showing. Whilst your viewpoint is perfectly justified, I do think it would be a bit more helpful if you could explain in a bit more depth than "because it didn't happen last time".

Happy Days - I imagine you admire anyone who's optimistic, full stop.

Model performance hasn't been great, and I am suggesting that they haven't improved all of a sudden just yet, sometimes they are good but sometimes not as has been the case. They may be right but there is too much 'belief' in their accuracy in FI.

BFTP

Ozzy its hard to be optimisitc when we see the same repetative output day after day week after week.

BTFP,Dec came in well above average with little or no snow for the majority(maybe vast majority)and a wasp was seen on stage at the darts,in late Dec.From a coldies POV,thats not great,is it.

:lol:

06z GFS continues the well established theme of +NAO dominance.

I'm a coldie and its been great winter so far, I have lived through many many mild Decembers and enjoyed what's followed. Dec just gone was far more interesting than say Dec 86.

BFTP

[kold weather]

Ensembles are very interesting later on, especially if you bear in mind the models are suggesting there will probably be another warming event. The GFS operational runs have refused to really entertain the weakening of the PV but the ensembles are overall quite different when it comes to the look of the Arctic.

Still for now there really isn;t anything other then hints on the models to grasp at. However what I will say is I've seen similar looking outlooks change quite quickly once the models get to grip with stratospheric conditions. I'm not saying the models have it wrong this time, but just keep it in mind!

[snowy owl]

Was the winter of Jan 84 not in a similar vain, mild December and cold snowy January? Can anyone point me in the direction of old NH charts for this period? If i remember rightly the evolution was not evident until early Jan and picked up fairly rapidly - can't see from the ordinary archive charts if there are any similarities to this years evolution?

Edited January 3, 2012 by snowy owl

[SP1986]

I've just looked at the ensembles from the GFS, and they are backing away from the cold clustering they were suggesting a few days ago, instead the main line of cluster is favouring something milder, in terms of trends. At the moment that is what they are showing, however whether they can be trusted with any confidence is another topic altogether. Here are the WZ ensembles for Manchester;

The control run continues to go for something much colder, however this is challenged by equally as persistent operational run, which continues to offer something milder. Obviously at this stage the control or operational are running the show, as the ensembles seem to be flirting in between each one.

[winterof79]

I admire anyone being optimistic in the face of some woeful model output again this morning! All 3 main models show a persistant cell of HP to our south and the limpet PV to the North West. At some point this pattern will have to break but it looks like ruining at least half (and probably more)the Winter this time round.

The GFS 06z Ensembles look far from "woeful" to my eyehttp://www.wetterzentrale.de/pics/MT8_Manchester_ens.png.With a definate trend downward by the 13th.I remember looking at previous ones in past winters waiting for the mean to drop to zero.Edit,i obviously cannot read them because i see a trend downward but SP sees it the other way.If the mean is then the majority also are. Edited January 3, 2012 by winterof79

[Timmytour]

They may be right but there is too much 'belief' in their accuracy in FI.

Two weeks ago, for today at this time, FI on GFS was showing high pressure centred just off the south west UK of 136mb.with all the UK higher than 120mb.

http://hw.nwstatic.co.uk/gfsimages/gfs.20111220/06/336/h850t850eu.png

I'm looking out the window at the horizontal rain thinking that might not have turned out to be the case!

But, as inaccurate as FI has been at times, it has been pretty consistent in the big picture of whether it's very cold or relatively mild.....And the extent to which it shows it staying mild is inversely proportional to the number of believers in an FI outcome! :-)

[weathe20]

The NAO and AO were (were) on a reasonble strong agreement heading for neautral and negative, this has slightly changed this morning to more neautral / positive. Also big disagreement between each ensemble.

Edited January 3, 2012 by weathe20

[kold weather]

Looking at the ensembles and the actual synoptics, changable is probably the best way to describe them, most have at least some cold shot at some point. Most keep the AO neutral/positive towards the back end but I never take that forecast too seriously, especially when there are background signals that would suggest something different beginning to occur.

[SP1986]

The GFS 06z Ensembles look far from "woeful" to my eyehttp://www.wetterzentrale.de/pics/MT8_Manchester_ens.png.With a definate trend downward by the 13th.I remember looking at previous ones in past winters waiting for the mean to drop to zero.Edit,i obviously cannot read them because i see a trend downward but SP sees it the other way.If the mean is then the majority also are.

The mean is a little higher than at was a few days ago, where the mean was often trending just above -5C on the 850's. Also the emergence of a ridge in temperature on the middle of the ensembles is a new trend that wasn't there a couple of days ago.. the trend from this new ridge is downwards on the 6z ensembles (and 0z to an extent), but still in the later runs it is slightly higher than it was a few days ago.

[Frosty.]

Again the date around 7-10th looks interesting and a return to raging zoneality

I wonder why we are heading back to raging zoneality after a quieter blip next week, the dripping tap effect of the strat warming appears to be making no difference to our weather, the FI charts on the gfs 00z look the same as they did when we had a cold stratosphere with mild or average zonal blasting the uk, I hope we see proper wintry weather at some point as there has been hardly any snow or frost so far.